1998 JAGUAR X308 engine ignition

E
lectronic Engine Controls -
Electronic Engine Controls
D
iagnosis and Testing
I

nspection and Verification
1.
1. Veri
fy the customer concern.
2. 2. Confirm which, if any, warning li ghts and/or messages were displayed on the instrument cluster.
• NOTE: If any warning lights and/or me ssages were displayed when the fault occurred, refer to the Driver Information
table for DTCs associated with the display, then to the DTC index table for possible sources and actions. Some warnings will
appear to clear when the ignition is cycl ed. This is often because the warning has flagged as a resu lt of one of the vehicle's
on-board diagnostic routines having run to detect the fault. If the same routine is not run when the ignition is switched ON,
the warning will not reflag until the routine does run. See the DTC summaries for drive cycle routines.
3. 3. Visually inspect for obvious signs of mechanical or electrical damage.
V
isual Inspection Chart
4.
4. Veri
fy the following syst
ems are working correctly:
Air in
take system
Coo

ling system
Charging system


F

uel charging system
5. 5. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding
to the next step.
6. 6. Where the Jaguar approved diagnostic sy stem is available, complete the S93 report before clearing any or all fault
codes from the vehicle.
• NOTE: If a DTC cannot be cleared, then there is a permanent fault present that flag s again as soon as it is cleared (the
exception to this is P1260, which will only clear following an ignition OFF/ON cycle after rectification).
7. 7. If the cause is not visually evident and the Jaguar approv ed diagnostic system is not available, use a fault code
reader to retrieve the fault codes be fore proceeding to the Diagnostic Trou ble Code (DTC) Index Chart, or the
Symptom Chart if no DTCs are set.
• NOTE: If the DTC flagged was not present for two or more co nsecutive cycles, it is classed as temporary, and will be
deleted following three cycl es during which no fault was present. This could result in a reported wa rning light/message with
no stored DTCs. If a fault is present for three consecutive cycles, the DTC becomes permanent, and will remain in the
module's memory for 40 drive cycles (a cy cle is an ignition ON/OFF, which will occur during the owner's normal use of the
vehicle. No action on the part of the technician is necessary to perform this cycle. A drive cycle is a series of conditions
needed to make the on-board diagnostic ro utine run, and may need a specific action on the part of the technician. See the
DTC summaries for driv e cycle routines).
8. 8. Using the Jaguar approved diagnostic system where available, and a scan tool where not, check the freeze frame
data for information on the conditions applicable when the fault was flagged. The format of this will vary,
dependin
g o
n the tool used, but can provide information useful to the technician in dia
gnos
in
g th
e fault.

MechanicalElectrical
Engi
ne oil level
Coo

ling system coolant
level
Fuel contamination

Throttle body Poly

-vee belt
F
uses
W

iring harness
E

lectrical connector(s)
Sens

or(s)
Engine

control module (ECM)
Tran

smission control module
Check spark plu

g type. Only re
sisted plugs should be fitted. Refer to specifications
section for gap
Relay date codes.
If the date on the rela
y is between R6 k1 and R6 k8, replace the
relay

CAUTIO
N: When probing connectors to take
measurements in the course of the pinpoint tests, use the adaptor kit,
part number 3548-1358-00.
• NOTE: When performing electrical voltag e or resistance tests, always use a digital multimeter (DMM) accurate to 3
decimal places, and with an up-t o-date calibration certificate. When testing resistance, always take the resistance of the
DMM leads into account.
• NOTE: Check and rectify basic faults before beginning diagnostic ro utines involving pinpoint tests.
Sym
ptom Chart
Sym

ptom
(general)
S y
mptom (specific)
Possib
l
e source
Acti
o
n
No
n
-Start
Engine
does not cran
k
Starter relay ECM relay Batt
ery Park
/Neutral
switch
Starting system

Harness damage
Engine s
iezed
Check r
e
lay dates. Check
for DTCS. For starting
system,
REFER to Section 303
-06 Sta r
ting System
.
F or ECM
relay tests, GO to Pinpoint Test
AD.
.
F o
r battery information,
REFER to Section 414
-0 1
Battery, Mounting and

Cables.
Fo r

Park/Neutral tests, GO to Pinpoint Test AC.
. Fo
r engine information,
REFER to Section 303
-01 En
gine
.
Engine cranks, but does
not fireSecurity
syst
em /Immobiliser
engaged
Thr o
ttle contaminated
Harness damage
Fu
el pump relay
Fue
l
system
R
e
fer to service action
S491
Contact dealer techni
cal
support for information
on security system. For fuel system,
REFER to Section 303
-0 4
Fuel Charging and
Controls.
Check bull etins for throttl
e cleaning procedure.
Check service actions.
Engine cranks an d
fires,
but will not start
F u
el pump relay
Thr
o
ttle contaminated
Purge
val
ve
Fue
l
pump
Engine coolan
t
temperature

(ECT) sensor
Spark plugs
fouled
Ignition coil
fail
ure(s)
Check f
o
r water ingress
into spark plug wells
HT sh o
rt to ground
(tracking) check rubber
boots for cracks/damage
Cyli
nder compression loss
(short-term. Refer to bulletin; 303-52)
Re
fer to service action
S491
Fo
r fuel pump relay tests,
REFER to Section 303
-0 4
Fuel Charging and
Controls.
. Check bulletins for throttl
e cleaning procedure.

Check fuel pressure. Refe r to Technical service
bulletins. For ECT sensor tests, GO to Pinpoint Test C.
. Fo
r ignition system,
REFER to Section 303
-07 En
gine Ignition
.
Check bulletins an d service a
ctions.
Di
f
ficult to
start
D iff
icult to start cold
Roc
h
ester valve
Batt
ery Thro
ttle contaminated
Fue
l
pump
Engine coolan
t
temperature

(ECT) sensor
Purge val
ve
Cyl
i
nder compression loss
(short-term. Refer to bulletin; 303-52)
Blocked part-load breather (s
ervice action S474)
R
e
fer to service action
S491
For R
ochester valv
e test, GO to Pinpoint Test AE.
. Fo
r battery information,
REFER to Section 414
-0 1
Battery, Mounting and

Cables.
Check bull etins for throttl
e cleaning procedure.
Check fuel pressure. For ECT sensor circuit tests,
GO to Pinpoint Test C.
. F
or evaporative
emissions tests,
REFER to Section 303
-1 3
Evaporative
Emiss
i
ons
.
R e
fer to bulletins for co
mpression information,
and service actions for part-load breather procedure and compressions.
Diff
icult to start hot
Roc
h
ester valve
Purge
val
ve
Thr
o
ttle contaminated
F
or R
ochester valv
e test, GO to Pinpoint Test AE.
. F
or evaporative emissions tests,
REFER to Section 303
-1 3
Evaporative

Driver Information
Chart
•

NOTE: Use this table to identify DTCs associated with the me
ssage center display, then refer to the DTC index for possible
sources and actions.
• NOTE: For definitions of Default Modes, see the foot of this table.
Poor
dr iveabilityEngine h e
sitates/poor
acceleration
Fue l
pump
Exhaus
t gas
recirculation
(EGR)
Air leakage Stop lamp swi t
ch
Throttl
e
sensors
Throttl
e
motor
Spark
plugs
fouled
Check f
o
r water ingress
into spark plug wells
Ignition coil fail
ure(s)
HT sh
o
rt to ground
(tracking) check rubber
boots for cracks/damage
ECM failu r
e
Check f
u
el pressure. For EGR information,
REFER to Section 303
-08 En gin
e Emission
Control.
F or i
ntake system information,
REFER to Section 303
-1 2
Intake Air Distribution

and F
ilt
ering
.
F or stop l
amp switch in
formation, refer to the
wiring diagrams. For throttle position sensor
tests,GO to Pinpoint Test D.
. Fo
r throttle motor
control circuit tests,GO to Pinpoint Test T.
. For
igni t
ion system,
REFER to Section 303
-07 En
gine Ignition
.
F or ECM
circuit tests,GO to Pinpoint Test
AD.
.
Engine backfiresFuel
pump
Air leakage MAF se

nsor
HO2 sensors
Spark plugs Check fo
r water ingress
into spark plug wells
HT sh o
rt to ground
(tracking) check rubber
boots for cracks/damage
Ignition coil fail
ure(s)
Chec
k fu
el pressure. For intake system
information,
REFER to Section 303
-12
Intake Air Distribution

and Filt
ering
.
F or MAF sensor ci
rcuit test
s,GO to Pinpoint Test
A.
. F or HO2 sensor
circui
t tests, check for DTC
indicating which sensor and follow indicated pinpoint test. For ignition system,
REFER to Section 303
-07 En
gine Ignition
.
Engine
s
urges
Air leakage
Fuel
pump
Stop lamp swit

ch
MAF s
e
nsor
Harness Throttl
e
sensors
Throttl
e
motor
Spark plugs
Check fo
r water ingress
into spark plug wells
HT sh o
rt to ground
(tracking) check rubber
boots for cracks/damage
ECM failu r
e
Fo
r
intake system,
REFER to Section 303
-1 2
Intake Air Distribution

and Filt
ering
.
Check fu
el pressure. For
stop lamp information,
refer to the wiring diagrams. For MAF sensor tests,GO to Pinpoint Test A.
. Fo
r throttle
position sensor tests,GO to Pinpoint Test D.
,
a n
dGO to Pinpoint Test
K.
. Fo
r throttle motor
circuit tests,GO to Pinpoint Test T.
. For ig
nition
system,
REFER to Section 303
-07 En
gine Ignition
.
F or ECM
circuit tests,GO to Pinpoint Test
AD.
.
Engine detonates/k
nocks
Fue
l
pump
HO2 sensors
Air leakage Blocked part-load breather
(s
ervice action S474)
Mass ai
r fl
ow (MAF) sensor
Chec
k fu
el pressure. Fo
r HO2 sensor circuit
tests, check for DTC indicating which sensor and
follow indicated pinpoint test. For intake system
information,
REFER to Section 303
-1 2
Intake Air Distribution

and Filt
ering
.
Check service action S474
. For MAF sensor
tests,GO to Pinpoint Test A.
.
No t
hrottle response
Traction contr
o
l invoked
Throttl
e
sensors
Throttl
e
motor
Fo
r th
rottle position sensor tests,GO to Pinpoint
Test D.
, andG O to Pinpoint
Test
K.
. Fo
r throttle

motor circuit tests,GO to Pinpoint Test T.
.
Cru i
se control inhibited or

disabled
Cru i
se control switch
Throttle

sensors
Stop lamp swit

ch
For cru
i
se control switches,
REFER to Section 310
-03
Speed Control
.
For th
rottle position sensor tests,GO to Pinpoint
Test D.
, andG O to Pinpoint
Test
K.
. For s t
op
light switch information, refer to the wiring diagrams.

cyl 8
P0222Thro
ttle position (TP) sensor
circuit 2 low voltage
TP se
nsor to ECM sensing circuit 2
(TP sensor pin 2) open circuit or
high resistance
TP sensor
failure
F
or TP sensor circ
uit tests,GO to
Pinpoint Test D.
, andG
O to Pinpoint
Test K.
.
P0223Thro
ttle position (TP) sensor
circuit 2 high voltage
TP se
nsor to ECM sensing circuit 2
(TP sensor pin 2) short circuit to
battery voltage
TP sensor
failure
F
or TP sensor circ
uit tests,GO to
Pinpoint Test D.
, andG
O to Pinpoint
Test K.
.
P0300Ran
dom misfire detected
ECM to
ignition module primary
circuit faults (cylinder misfire
detected DTCs also logged)
Igni
tion module to ignition coil
primary circuit fault(s) (cylinder
misfire DTC also logged)
Ignition modu
le ground circuit;
open circuit, hi gh resistance
Ignition coil
failure(s)
Ignition modul

e failure(s)
Check f

or water ingress into spark
plug wells
HT sho
rt to ground (tracking)
check rubber boots for
cracks/damage
Spark plug
failure/fouled/incorrect
gap
Cy
linder compression low
F

uel injector circuit fault(s)
(injector DTCs also logged)
F
uel delivery pressure (low/high)
F

uel injectors restricted/leaking
Fuel contamination


P

AS pulley bolts loose (see Service
Action S462)
W
orn camshaft/broken valve
springs
F
or ignition circuit tests,
REFER to Section 303
-07
Engine
Ignition.
F
or engine information,
REFER to Section 303
-00
Engine
Sy

stem
- General
Information
.
F
or fuel system information,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
Check service
actions.
P0301Mis

fire detected, cyl 1
R
efer to possible sources for P0300
R
efer to actions for P0300.
P0302Mis

fire detected, cyl 3
P0303Mis

fire detected, cyl 5
P0304Mis

fire detected, cyl 7
P0305Mis

fire detected, cyl 2
P0306Mis

fire detected, cyl 4
P0307Mis

fire detected, cyl 6
P0308Mis

fire detected, cyl 8
P0327Right

-hand knock sensor (KS)
sense circuit out of range (low
voltage)
Poor sensor cont
act with cylinder
block
KS to
ECM sense circuit short
circuit to ground
KS fai
lure
F
or right-hand knock sensor circuit
tests,GO to Pinpoint Test L.
.
P0328Right
-hand knock sensor (KS)
sense circuit out of range (high
voltage)
Poor sensor cont
act with cylinder
block
KS to EC
M sense circuit high
resistance or open circuit
KS to
ECM sense circuit short
circuit to high voltage
KS fai
lure
F
or right-hand knock sensor circuit
tests,GO to Pinpoint Test L.
.
P0332Left-hand knock sens
or (KS) sense

circuit out of range (low voltage)
Poor sensor cont
act with cylinder
block
KS to
ECM sense circuit short
circuit to ground
KS fai
lure
F
or left-hand knoc
k sensor circuit
tests,GO to Pinpoint Test M.
.
P0333Left-hand knock sens
or (KS) sense

circuit out of range (high voltage)
Poor sensor cont
act with cylinder
block
KS to EC
M sense circuit high
resistance or open circuit
KS to
ECM sense circuit short
circuit to high voltage
F
or left-hand knoc
k sensor circuit
tests,GO to Pinpoint Test M.
.

KS fail
ure
P0335Cranksh
a
ft positi
on (CKP) sensor
circuit malfunction
CK P
sensor disconnected
CKP sensor air gap
i
n
correct/foreign matter on face
CKP sensor sen
s
ing circuit open
circuit, short circuit to ground,
short circuit to high voltage
CKP s e
nsor failure
F
or CKP sensor circ ui
t tests,GO to
Pinpoint Test N.
.
P0340Camshaft position
(CMP) sensor
circuit malfunction
CM P
sensor disconnected
CMP sensor air gap
i
n
correct/foreign matter on face
CMP sensor sen
s
ing circuit open
circuit, short circuit to ground,
short circuit to high voltage
CMP s e
nsor failure
F
or CMP sensor circ ui
t tests,GO to
Pinpoint Test O.
.
P0351Igniti
on coil primary/secondary
circuit malfunction, cyl 1
ECM to ignit
ion module primary
circuit open circuit, short circuit to
ground, high resistance
Igniti
on module to ignition coil
primary circuit open circuit, short
circuit to ground, high resistance
Ignition modu le
ground circuit
open circuit, hi gh resistance
Ignition coil fail
ure
Ignition modul
e
failure
F
o
r ignition circuit tests,
REFER to Section 303
-07 En
gine
Ignition. P0352Ignit
i
on coil primary/secondary
circuit malfunction, cyl 3
P0353Ignit i
on coil primary/secondary
circuit malfunction, cyl 5
P0354Ignit i
on coil primary/secondary
circuit malfunction, cyl 7
P0355Ignit i
on coil primary/secondary
circuit malfunction, cyl 2
P0356Ignit i
on coil primary/secondary
circuit malfunction, cyl 4
P0357Ignit i
on coil primary/secondary
circuit malfunction, cyl 6
P0358Ignit i
on coil primary/secondary
circuit malfunction, cyl 8
P0400Exhaus t gas
recirculation (EGR)
flow malfunction
EGR valve c
onnector pins high
resistance
EGR pipe/exhaust manifol
d leak
EGR pipe blocke

d
EGR valve st

uck open/closed,
blocked
EGR valve fai
lure
For EGR
pinpoint t
ests,
REFER to Section 303
-08 En
gine
Emission Control.
P0405Exhaus
t gas
recirculation (EGR)
drive circuits open circuit
EGR valve power supply circuit
o p
en circuit
EGR valve t
o
ECM drive circuit pair
- EGR pins 1/3, 4/6 open circuit,
high resistance
EGR val v
e failure (stepper motor
open circuit)
For EGR pinpoint t
ests,
REFER to Section 303
-08 En
gine
Emissi
on Control.
P0406Exhaus t gas
recirculation (EGR)
drive circuits short circuit
EGR valve t o
ECM drive circuit pair
- EGR pins 1/3, 4/6 short circuit to
ground or high voltage
EGR val v
e failure (stepper motor
short circuit)
For EGR pinpoint t
ests,
REFER to Section 303
-08 En
gine
Emissi
on Control.
P0420Right-
hand catalytic converter
efficiency below threshold
HO2S di
sconnected.
HO2
S
to ECM wiring fault.
HO2
S
heater to ECM wiring fault.
HO2
S
heater failure.
HO2
S
failure.
Cat
a
lyst monitor sensor failure.
Catal
y
tic converter failure.
R
e
fer to pinpoint tests for components

listed. Visually inspect catalytic
converters.
P0442Evaporati v
e emissions system
(EVAP) leak detected
Fue l
filler cap missing
Fu

el filler cap seal faulty
EVAP system
leak (can
ister
damage, pipework damage)
EVAP v a
lve to ECM drive circuit
open circuit, short circuit, high
resistance
EVAP valve to engine pu rge pipe
damaged/blocked/leaking
EVAP ope r
ating vacuum hose
F
or evaporati
ve emissions pinpoint
tests,
REFER to Section 303
-1 3
Evaporative

Emissi
ons
.

TP se
nsor to ECM sensing circuits
('1' or '2') short circuit to high
voltage
TP sensor
failure
Throttl

e motor disconnected
Th

rottle motor to ECM drive circuits

short circuit or open circuit
Throttl
e motor failure
Throttl

e assembly failure
Test
K. . F
or throttle motor circuit
tests,GO to Pinpoint Test T.
. For
throttle body i
nformation,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
P1252Mec

hanical gu
ard position
malfunction (cruise (speed)
control)
VSV 1, 2, 3 v
acuum and/or
electrical circuit fault(s) open
circuit, short circuit or high
resistance
Mechanica
l guard sensor to ECM
sense circuit
Mechanica
l guard sensor failure
Mechanica

l guard actuator
siezed/spring broken
Throttl
e vacuum actuator fault
Se
e pinpoint tests for components
listed.
P1253Mec
hanical gu
ard position
malfunction (engine off)
VSV 1, 2, 3 v
acuum and/or
electrical circuit fault(s)
Mechanica
l guard sensor to ECM
sense circuit
Mechanica
l guard sensor failure
Mechanica

l guard actuator
siezed/spring broken
Throttl
e vacuum actuator fault
Se
e pinpoint tests for components
listed.
P1260Se
curity input malfunction
K
TM to ECM circuit short circuit,
high resistance or open circuit
KTM failu
re
F
or KTM circuit tests,GO to Pinpoint
Test Y.
.
P1313M
isfire rate catalyst damage,
right-hand. NOTE: This DTC will
flag only when accompanied by a
random or individual cylinder
misfire DTC; P0300, P0301 to
P0304
R
efer to possible causes for P0300-P0308
R
efer to actions for P0300-P0308.
P1314Mi

sfire rate catalyst damage, left-
Hand: NOTE. This DTC will flag
only when accompanied by a
random or individual cylinder
misfire DTC; P0300 to P0308
P1316M
isfire excess emission. NOTE:
This DTC will flag only when
accompanied by an individual
cylinder misfire DTC; P0300 to
P0308
P1336Cranksh
aft position
(CKP) sensor /
camshaft position (CMP) sensor
synchronization malfunction
CKP s
ensor/CMP sensor
disconnected
CKP sensor/CM
P sensor gap
incorrect/foreign matter on sensor
face
CKP s
ensor/CMP sensor sensing
circuit open circuit, short circuit to
ground, short circuit to high
voltage
CKP s
ensor/CMP sensor failure
F
or CKP sensor circ
uit tests,GO to
Pinpoint Test N.
. For CM
P sensor
circuit tests,GO to Pinpoint Test O.
.
P1367Ignit
ion monitor (ignition module
1)
Ignition modu
le
1 disconnected
Ignition modul
e 1 to ECM circuits
open circuit, short circuit to ground
or short circuit to B+ voltage
Ignition modul
e 1 ground circuit
fault
Ignition coil
relay failure
Ignition coil

open/short circuit
Ignition modul

e 1 failure
F
or ignition circuit tests,
REFER to Section 303
-07
Engine
Ignition.
P1368Ignit

ion monitor (ignition module
2)
Ignition modu
le
2 disconnected
Ignition modul
e 2 to ECM circuits
open circuit, short circuit to ground
F
or ignition circuit tests,
REFER to Section 303
-07
Engine
Ignition.

or sho
rt circuit to B+ voltage
Ignition modul
e
2 ground circuit
fault
Ignition coil relay fai
lure
Ignition coil
open/short
circuit
Ignition modul
e
2 failure
P1474Int
e
rcooler coolant pump relay
malfunction
Intercooler pump relay failure

Intercooler pump relay
to ECM

drive circuit fault
Intercooler pump relay coi
l ground
circuit fault
ECM power supply f
ault
F
or i
ntercooler pump relay circuit
tests,GO to Pinpoint Test Z.
.
P1475Ra
diator fans slow
(series) circuit
malfunction
R a
diator fan control relay module
to ECM 'series' drive circuit (relay
pin 9) fault
Relay coil ignition power supply
o p
en circuit
ECM ground circuit fault (relay coil


drive)
ECT se ns
or circuit malfunction
(refer to P0116)
F o
r radiator fan seri
es circuit tests,GO
to Pinpoint Test AA.
P1476Ra
diator fans fast (parallel) circuit
malfunction
R a
diator fan control relay module
to ECM 'parallel' drive circuit (relay
pin 7) fault
Relay coil ignition power supply
o p
en circuit
ECM ground circuit faul
t (relay coil

drive)
ECT sens
or circuit malfunction
(refer to P0116)
F or radi
ator fan parallel circuit
tests,GO to Pinpoint Test AB.
.
P1516Gear change PARK
/NEUTRAL

driving malfunction
Transmission range (T
R) sensor to
ECM circuit open circuit or high
resistance
TR sensor f
ailure
D-
4
switch to TCM circuit open
circuit or high resistance
D-4 swi
tch fault
For

PARK/NEUTRAL tests,GO to
Pinpoint Test AC.
.
P1517Engine PA
RK/NEUTRAL
cranking
malfunction
Transmissi on range (T
R) sensor to
ECM circuit open circuit or high
resistance
TR sensor f
ailure
Fo
r

PARK/NEUTRAL tests,GO to
Pinpoint Test AC.
.
P1571Brake swit
ch malfunction
Brake sw
it
ch to ECM circuit open
circuit, short circ uit to ground, high
resistance
Brake sw it
ch ignition switched
ground circuit open circuit
Brake sw it
ch failure
Brake ca
ncel
switch to ECM circuit
open circuit, short circuit to
ground, high resistance
Brake ca nce
l switch to cruise
(speed) control switch circuit open
circuit, short circ uit to ground, high
resistance
Brake cance
l switch ignition
switched power supply open circuit
Brake ca nce
l switch failure
Cru
i
se (speed) control switch
failure
For cru i
se (speed) control circuit tests,
REF
E
R to Section 310
-03
Sp
eed
Control.
P1606Engine
m
anagement system
(EMS) control relay malfunction
ECM co ntrol rel
ay failure
ECM c
o
ntrol relay to ECM circuit
fault
ECM co ntrol rel
ay coil power supply

open circuit
ECM ground circuit faul t (relay coil

drive)
F or ECM
relay circuit tests,GO to
Pinpoint Test AD.
.
P1609EC
M microprocessor-to-
microprocessor communication
ECM failu r
e
Contact deal
er techni
cal support for
advice on possible ECM failure.

Pinpoint Tests
f
ailure
P1611Thr

ottle angle malfunction
TP sensor
circuit fault (refer to
P0121)
APP sensor circuit faul
t (refer to
P0121)
Throttl
e assembly failure
ECM failu

re
Se
e pinpoint tests for components
listed. For throttle body information,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
Contact deal
er technical support for
advice on possible ECM failure.
P1612Throttl
e offset malfunction
TP sensor
circuit fault (refer to
P0121)
APP sensor circuit faul
t (refer to
P0121)
Throttl
e assembly failure
ECM failu

re
Se
e pinpoint tests for components
listed. For throttle body information,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
Contact deal
er technical support for
advice on possible ECM failure.
P1637CAN AB
S/TCCM token missing
CAN
open circuit fault - ABS/TCCM
to ECM
CAN s
hort circuit fault
ABS/TCCM failu

re
ECM failu

re
F
or network circuit tests,
REFER to Section 418
-00
Module
Comm

unications Network
.
P1638CAN INST token missingCAN

open circuit fault - INST to
ECM
CAN s
hort circuit fault
INST

failure
ECM failu

re
F
or network circuit tests,
REFER to Section 418
-00
Module
Comm

unications Network
.
P1642CAN c

ircuit malfunction
CAN s
hort circuit fault
Control modul

e failure - check for
additional logged DTCs to locate
control module source
F
or network circuit tests,
REFER to Section 418
-00
Module
Comm

unications Network
.
P1643CAN TC

M token missing
CAN
open circuit fault - TCM to
ECM
CAN s
hort circuit fault
TCM failure


ECM failu

re
F
or network circuit tests,
REFER to Section 418
-00
Module
Comm

unications Network
.
P1646F

uel pump 2 relay malfunction.
NOTE: This DTC applies only to
the S/C fuel pump 2
F
uel pump 2 relay failure
F

uel pump 2 relay to ECM circuit
fault
F
uel pump 2 relay coil power
supply open circuit
ECM ground circuit faul
t (relay coil
drive)
F
or fuel pump 2 relay circuit tests,
REFER to Section 303
-04
Fuel
Charging and Con

trols
.
P

INPOINT TEST A : DTC P0101, P0102, P0103; MASS AIR FLOW (MAF) SENSOR
RANGE/PERFORMANCE, HIGH/LOW VOLTAGE
•
NOTE: Before commencing this
test, check the air filter for blockage, the engine air inta ke and breather systems for
leaks, and the TPS for additional DTCs.
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
A1: CHECK

THE MAF SENSOR SENS
E CIRCUIT FOR HIGH RESISTANCE
Di
sconnect the battery negative terminal.
1
D

isconnect the ECM electrical connector, EM12.
2
Di

sconnect the MAF sensor electrical connector, PI35.
3
Meas

ure the resistance between EM12, pin 13 (GY) and PI35, pin 02 (GY).
4
Is th

e resistance greater than 5 ohms?
Yes REPAIR the high resistance circuit. For additional information, refer to the wiring diagrams. CLEAR the
DTC. TEST the system for normal operation.
No GO to A2
.
A2: CHECK
THE MAF SENSOR SENSE CI
RCUIT FOR SHORT TO HIGH VOLTAGE
R
econnect the battery negative terminal.
1
Turn the ignition swi

tch to the ON
position.
2
M
easure the voltage between the MAF sensor electrical connector, PI35, pin 02 (GY) and GROUND.
3
Is th

e voltage greater than 3 volts?